Abstract Nowadays, the third part of parrots in the world is endangered or vulnerable; an alternative for their preservation is assisted reproduction in captivity through hormonal manipulation. In birds, GnRH is the main hormone which controls reproductive physiology, it is known there are three types: GnRH-I, GnRH-II and GnRH-III, involved in the release or inhibition of luteinizing hormone and follicle stimulant hormone to control gonadal and gametic development. The objective of this study was, to evaluate the effect of administrating synthetic GnRH-I in the testicular development of Melopsittacus undulatus. Twenty-eight adult budgerigars were randomly divided in two groups: control (n=14) and treated (n=14) with a unique dose of synthetic GnRH-I. Testicular development was assessed through ultrasonography and density was evaluated with pixels. Germinal diameter and thickness of germinal epithelium were determined with histology; there were identified and countified different cellular strains in seminiferous tubules therefore spermatobioscopy. Results. Ecographic density was: control group: 76 ± 7 pixels, treated group 41 ± 3 pixels. Thickness of germinal epitellium, 51.5 ± 2.9µm and 73.1 ± 3.1µm, for control group and treated group respectively. Sperm concentration in the treated group was 300% superior than in control group. It is concluded that the administration of synthetic GnRH-I, is a viable alternative to be used as part of the assisted reproductive techniques to induce reproduction.

ABSTRACT It is important to design efficient, practical and easy to perform techniques to assess the acrosomal integrity of the sperm. The objective was to modify the Giemsa staining technique for acrosomal NAR assessment in mammalian sperm. 140 lamellae of spermatozoa from 4 different mammals (bovine, ovine, porcine and human) were evaluated, divided into two groups (70 lamellae per group). The first group was evaluated acrosomal NAR with the classic technique of Giemsa staining and the second, with the modified Giemsa technique. The means of acrosomal NAR and the times of each of the techniques were compared. There was no difference between the means of acrosomal NAR in both techniques (p<0.05); however, while the conventional technique takes 115 minutes, the time of realization of the modified technique was 35 minutes, reducing the time 80 minutes, with better image clarity. In conclusion, the modified staining technique decreases the NAR titration time and shows a better sharpness of the image.

RESUMEN Es importante diseñar técnicas eficientes, prácticas y fáciles de realizar para valorar la integridad acrosomal de los espermatozoides. El objetivo fue evaluar la técnica modificada de tinción Giemsa para valoración del borde apical normal (NAR) en espermatozoides de mamíferos. Se evaluaron 140 laminillas de espermatozoides de 4 diferentes mamíferos (bovinos, ovinos, porcinos y humanos), se dividieron en dos grupos (70 laminillas por grupo). El primer grupo, se evaluó NAR con la técnica clásica de tinción Giemsa y el segundo, con la técnica modificada de Giemsa. Se compararon los porcentajes de acrosomas NAR y los tiempos de cada una de las técnicas. No hubo diferencia entre las medias de acrosomas NAR en ambas técnicas (p<0.05); sin embargo, mientras la técnica convencional tarda 115 min, el tiempo de realización de la técnica modificada fue de 35 minutos, reduciendo el tiempo 80 minutos, con una mejor claridad de la imagen. En conclusión, la técnica de tinción modificada disminuye el tiempo de valoración de NAR y muestra una mejor nitidez de la imagen.